Door check means



y 30, 1967 v KIYQSHI NAGAI 3,322,453

DOOR CHECK MEANS Filed June 1, 1965 United States Patent 3,322,453 DOOR CHECK MEANS Kiyoshi Nagai, 267 Kugahara-machi, Ota-ku, Tokyo, Japan Filed June 1, 1965, Ser. No. 460,447

1 Claim. (Cl. 292-269) This invention relates to door check means.

An object of the invention is to provide such door check that a door cannot be opened by more than a planned amount to prevent undesired access.

Another object of the invention is to provide such door check means that a door can be freely opened and closed when desired.

Another object of the invention is to provide door check means which is easy and reliable to operate.

Another object of the invention is to provide door check means which can not be unfastened when the means is in acting position even if a lawless person tries to unfasten the means to open the door from outside.

Another object of the invention is to provide door check means free from dangerous protruding members likely to catch ones coat or clothing by fitting the check bolt within the door and engaging the swinging key plate flush to the door jamb.

A further object of the invention is to provide a door check means which can be provided at low price.

The invention is illustrated by way of example in the accompanying drawings, in which:

FIG. 1 is a partial perspective view of the door check means on a door and jamb, the spacing between the door and the jamb being somewhat exaggerated compared with its normal spacing;

FIG. 2 is a longitudinal sectional view of the door check means which is in a state ready for engaging; and

FIG. 3 is a front elevational view of the door check means of the side on the jamb which is in a engaged position prior the opening action of the door.

In the drawing 1 is a door bolt having a head 1a at its one end and a neck 1b, formed with a neck slot 2, and 3 is a guide cylinder into which the bolt 1 is slidably fitted. The cylinder 3 is inserted into a groove 4 in a door 5 and is fixed on a side face of the door 5 by means of screws 6 extending through flange 7 provided at the outer end of the cylinder 3. The bolt 1 is thus fitted into the cylinder 3, the head In of the bolt 1 being capable of protruding outwards from the cylinder 3. To the bolt 1 there fixed, for example by screw means, a knob 8 which passes through and protrudes outwards of an opening 9 provided on one side of the door 5 and communicating with said groove 4.

10 is a key plate, which is pivoted to swing by means of a pivot pin 11 on a base-plate 12 at an upper portion on the center line C, both the key plate 10 and the base-plate 12 being inseparably connected for instance by caulking the end of the pivot pin 11. There is formed a long key slot 13 through the key plate 10 along its center line C, at the upper portion of which is made as a large diametral hole 14 so that the head 1a of the bolt 1 may engage with the key plate 10 and the other portion 13 of which has a Width passable only for the neck 1b of the bolt 1. On the back of the key slot 13, there provided recesses 15a which start from the lower ends of the key slot 13 and terminate near the circumference of the hole 14, to permit the head In of the bolt 1 to move within the recesses 15a,

3,322,453 Patented May 30, 1967 keeping the engagement between the bolt 1 and the key plate 10. The base-plate 12 is inserted into a recess 16 provided in jamb 17 in such manner that it is flush with the jamb 17 and in such manner that the hole 14 through the key plate 10 locates, at the closed position of the door 5, on the passage along which the bolt 1 moves. The baseplate 12 is fixed on the jamb 17 by means of screws or the like 18 through setting holes 19 bored through the baseplate 12. At least one or two of those setting holes 19 are bored within an area limited by a circumference of a window 20 passing through the key plate 10, so that those holes 19 are to be covered with the back face 10a of the key plate 10 when the key plate 10 is in a tilted position and the screws 18 may be taken out through the holes 19 only when the key plate 10 takes the vertical position.

If at this juncture the length of the recess 16 into which the base-plate 12 is to be set is the same as the length of the key plate 10, it is necessary for permitting swing of the key plate 10 to shape an are on its lower end with a radius R, having its center on the line C, equal to or less than a length between the pivot pin 11 and the lower end of the key plate 10 along the center line C.

Now the functions of the door check means according to the invention will be described in greater detail.

In the state where the bolt 1 is caused to retreat into the door 5, the door 5 and the jamb 17 are disconnected from each other because the head 1a of the bolt 1 is out of the key slot 13. Hence the door 5 may be freely opened and closed.

When bolt 1 protrudes outwards from the door 5 due to displacement of the knob 9, the head 1a of the bolt 1 enters into the hole 14 of the key plate 10 and stops at the position where the head 1a comes into contact with the baseplate 12. Hence if the door 5 is opened, it moves, keeping the head 1a of the bolt 1 in engagement with the hole 14, so that the bolt 1 causes the key plate 10 to swing around the pivot pin 11 and the bolt 1 itself slides out of hole 14 and into the keyhole 13. This causes the head 1a to slide into the recesses 15a and 15b, which secures a perfect engagement with the bolt 1 and the key plate 10. When the bolt 1 reaches the lower end of the key slot 13, the bolt 1 is stopped so that the door 5 also is stopped.

If an unauthorized person tries to take oil the base-plate 12 in this half-opened state of the door 5, he will not be able to enter because the screws or the like 18 have been covered with the back face 10a of the key plate 10.

In the door check means the bolt 1 should be placed in a position capable of engaging with the key plate 10. On the occasion of visitation by a stranger, a resident may let him into the house, opening the door 5 freely after retreat of the bolt 1 in the closed state of the door 5, upon making sure of the stranger.

According to the invention as above described, many objects have been accomplished. While there has been disclosed in the specification one form of the invention, the invention is not to be limited to the specific disclosure, but may be modified and embodied in various other forms without departing from its spirit.

What is claimed is:

For use with a door and jamb having opposed faces, a door check comprising a bolt including a head encircled by an annular slot, means supporting the bolt in said door such that said head can be extended towards said '3 C3 jamb, a fiat base plate set in said jamb, a fiat check plate, a pin pivotally supporting said check plate in face-to-face relationship with said base plate and check plate retaining said relationship throughout all pivotal movements of said check plate, said base plate being provided with a hole having a rectilinear keyway extending therefrom, said hole being aligned with said bolt to receive said head, said key- Way receiving said head With play upon pivoting of said check plate whereby pivotal displacement of said door is accommodated, said check plate including a free end portion having a radius equal to the distance between the axis of said pin and the corresponding extremity of said base plate.

References Cited UNITED STATES PATENTS 388,074 8/1888 Reardon et al 292-269 5 1,673,189 6/1928 Frank et a1 292-268 2,030,916 2/1936 Gard 292-269 2,888,720 6/1959 Farmer 292-262 X MARVIN A. CHAMPION, Primary Examiner.

1O RICHARD E. MOORE, Examiner. 

